The present embodiments relate to artifact reduction in ultrasound imaging. In particular, artifacts from three-dimensional ultrasound imaging are reduced.
Three-dimensional perfusion parametric images of ultrasound contrast agents are useful for studying variations in blood flow in organs and tissues in response to disease states, drugs, or other physiological conditions. For volume perfusion parametric imaging, contrast agent is introduced into the bloodstream. A region is then imaged in a non-destructive contrast sensitive mode to measure a blood perfusion parameter, such as contrast agent arrival time, maximum intensity projection, normalized time integral, or maximum area coverage. Other types of parametric imaging where a characteristic of acoustic response over time is calculated are known.
For ultrasound imaging of a volume, different parts of the volume are scanned over time. However, if there is significant motion during consecutive acquisitions, then the values of the parameters may be based on returns from different locations rather than the same location. One way to avoid motion is to have the user hold their breath. Collecting sufficient data for parametric imaging may require the patient to hold their breath for too long. For example, contrast wash-in and wash-out takes place over 30 seconds to 4 minutes. The offset in data caused by breathing may be countered by motion tracking. However, motion tracking may be ineffective due to a low sampling rate of the volume. Beamformer data rates may be low, such as sub-Hertz. Improvements to beamformer data rates may permit volume rates on the order 5-10 Hertz, which is still too low for good quality tracking without significant geometric distortion.